This invention relates to rechargeable batteries, and more particularly to analyzing nickel cadmium batteries for memory effect. Nickel cadmium batteries suffer from a phenomenon often referred to as the memory effect. The memory effect is the tendency of the battery to adjust its electrical properties to a certain duty cycle to which it has been subjected to for an extended period of time. See, T. R. Crompton, Battery Reference Book, 2nd Edition, Chapter 19, page 11, Reed Educational and Professional Publishing, Ltd. The battery provides power at a lower voltage when used beyond this duty cycle. Subsequently, this low power usage limits the useful energy available from the battery. The memory effect is noticed in actual usage only when one tries to use the battery's full capacity after several cycles of partial discharge, but the battery usage time with acceptable voltage is limited by the lower voltage under load.
At the present time, there is no method for determining whether a nickel cadmium battery is stricken with the memory effect without performing a complete discharge.
There is, therefore, a need to detect the memory effect in a completely charged nickel cadmium battery without performing a full discharge.